feat(client): allow updating span/generation name (#1255)

Author: hassiebp

langfuse/_client/client.py

@@ -773,6 +773,7 @@ def _get_current_otel_span(self) -> Optional[otel_trace_api.Span]:
     def update_current_generation(
         self,
         *,
+        name: Optional[str] = None,
         input: Optional[Any] = None,
         output: Optional[Any] = None,
         metadata: Optional[Any] = None,
@@ -793,6 +794,7 @@ def update_current_generation(
         details that become available during or after model generation.
 
         Args:
+            name: The generation name
             input: Updated input data for the model
             output: Output from the model (e.g., completions)
             metadata: Additional metadata to associate with the generation
@@ -835,6 +837,9 @@ def update_current_generation(
                 otel_span=current_otel_span, langfuse_client=self
             )
 
+            if name:
+                current_otel_span.update_name(name)
+
             generation.update(
                 input=input,
                 output=output,
@@ -853,6 +858,7 @@ def update_current_generation(
     def update_current_span(
         self,
         *,
+        name: Optional[str] = None,
         input: Optional[Any] = None,
         output: Optional[Any] = None,
         metadata: Optional[Any] = None,
@@ -867,6 +873,7 @@ def update_current_span(
         that become available during execution.
 
         Args:
+            name: The span name
             input: Updated input data for the operation
             output: Output data from the operation
             metadata: Additional metadata to associate with the span
@@ -905,6 +912,9 @@ def update_current_span(
                 environment=self._environment,
             )
 
+            if name:
+                current_otel_span.update_name(name)
+
             span.update(
                 input=input,
                 output=output,

langfuse/_client/span.py

@@ -561,6 +561,7 @@ def __init__(
     def update(
         self,
         *,
+        name: Optional[str] = None,
         input: Optional[Any] = None,
         output: Optional[Any] = None,
         metadata: Optional[Any] = None,
@@ -575,6 +576,7 @@ def update(
         during execution, such as outputs, metadata, or status changes.
 
         Args:
+            name: Span name
             input: Updated input data for the operation
             output: Output data from the operation
             metadata: Additional metadata to associate with the span
@@ -607,6 +609,9 @@ def update(
             data=metadata, field="metadata", span=self._otel_span
         )
 
+        if name:
+            self._otel_span.update_name(name)
+
         attributes = create_span_attributes(
             input=processed_input,
             output=processed_output,
@@ -1048,6 +1053,7 @@ def __init__(
     def update(
         self,
         *,
+        name: Optional[str] = None,
         input: Optional[Any] = None,
         output: Optional[Any] = None,
         metadata: Optional[Any] = None,
@@ -1069,6 +1075,7 @@ def update(
         token usage statistics, or cost details.
 
         Args:
+            name: The generation name
             input: Updated input data for the model
             output: Output from the model (e.g., completions)
             metadata: Additional metadata to associate with the generation
@@ -1123,6 +1130,9 @@ def update(
             data=metadata, field="metadata", span=self._otel_span
         )
 
+        if name:
+            self._otel_span.update_name(name)
+
         attributes = create_generation_attributes(
             input=processed_input,
             output=processed_output,

tests/test_otel.py

@@ -309,6 +309,23 @@ def test_span_hierarchy(self, langfuse_client, memory_exporter):
         # All spans should have the same trace ID
         assert len(set(s["trace_id"] for s in spans)) == 1
 
+    def test_update_current_span_name(self, langfuse_client, memory_exporter):
+        """Test updating current span name via update_current_span method."""
+        # Create a span using context manager
+        with langfuse_client.start_as_current_span(name="original-current-span"):
+            # Update the current span name
+            langfuse_client.update_current_span(name="updated-current-span")
+
+        # Verify the span name was updated
+        spans = self.get_spans_by_name(memory_exporter, "updated-current-span")
+        assert len(spans) == 1, "Expected one span with updated name"
+
+        # Also verify no spans exist with the original name
+        original_spans = self.get_spans_by_name(
+            memory_exporter, "original-current-span"
+        )
+        assert len(original_spans) == 0, "Expected no spans with original name"
+
     def test_span_attributes(self, langfuse_client, memory_exporter):
         """Test that span attributes are correctly set and updated."""
         # Create a span with attributes
@@ -360,6 +377,23 @@ def test_span_attributes(self, langfuse_client, memory_exporter):
             == "Test status"
         )
 
+    def test_span_name_update(self, langfuse_client, memory_exporter):
+        """Test updating span name via update method."""
+        # Create a span with initial name
+        span = langfuse_client.start_span(name="original-span-name")
+
+        # Update the span name
+        span.update(name="updated-span-name")
+        span.end()
+
+        # Verify the span name was updated
+        spans = self.get_spans_by_name(memory_exporter, "updated-span-name")
+        assert len(spans) == 1, "Expected one span with updated name"
+
+        # Also verify no spans exist with the original name
+        original_spans = self.get_spans_by_name(memory_exporter, "original-span-name")
+        assert len(original_spans) == 0, "Expected no spans with original name"
+
     def test_generation_span(self, langfuse_client, memory_exporter):
         """Test creating a generation span with model-specific attributes."""
         # Create a generation
@@ -394,6 +428,27 @@ def test_generation_span(self, langfuse_client, memory_exporter):
         )
         assert usage == {"input": 10, "output": 5, "total": 15}
 
+    def test_generation_name_update(self, langfuse_client, memory_exporter):
+        """Test updating generation name via update method."""
+        # Create a generation with initial name
+        generation = langfuse_client.start_generation(
+            name="original-generation-name", model="gpt-4"
+        )
+
+        # Update the generation name
+        generation.update(name="updated-generation-name")
+        generation.end()
+
+        # Verify the generation name was updated
+        spans = self.get_spans_by_name(memory_exporter, "updated-generation-name")
+        assert len(spans) == 1, "Expected one generation with updated name"
+
+        # Also verify no spans exist with the original name
+        original_spans = self.get_spans_by_name(
+            memory_exporter, "original-generation-name"
+        )
+        assert len(original_spans) == 0, "Expected no generations with original name"
+
     def test_trace_update(self, langfuse_client, memory_exporter):
         """Test updating trace level attributes."""
         # Create a span and update trace attributes
@@ -514,6 +569,25 @@ def test_complex_scenario(self, langfuse_client, memory_exporter):
         assert llm_input == {"prompt": "Summarize this text"}
         assert llm_output == {"text": "This is a summary"}
 
+    def test_update_current_generation_name(self, langfuse_client, memory_exporter):
+        """Test updating current generation name via update_current_generation method."""
+        # Create a generation using context manager
+        with langfuse_client.start_as_current_generation(
+            name="original-current-generation", model="gpt-4"
+        ):
+            # Update the current generation name
+            langfuse_client.update_current_generation(name="updated-current-generation")
+
+        # Verify the generation name was updated
+        spans = self.get_spans_by_name(memory_exporter, "updated-current-generation")
+        assert len(spans) == 1, "Expected one generation with updated name"
+
+        # Also verify no spans exist with the original name
+        original_spans = self.get_spans_by_name(
+            memory_exporter, "original-current-generation"
+        )
+        assert len(original_spans) == 0, "Expected no generations with original name"
+
     def test_custom_trace_id(self, langfuse_client, memory_exporter):
         """Test setting a custom trace ID."""
         # Create a custom trace ID